Blockstream Research Demonstrates Quantum-Resistant Transaction Signing on Liquid Using Simplicity Smart Contracts

Blockstream Research reports verifying a post-quantum signature scheme — SHRINCS, a hash-based design — inside a Simplicity smart contract and broadcasting the resulting transactions on the Liquid Network. It is framed as a practical proof that hash-based signatures can be checked on a live bitcoin-adjacent chain today, including stateful and stateless fallback modes.

The post is careful about scope: it protects transaction signing only, runs on a sidechain (not bitcoin mainnet, where Simplicity is not available), and is described as an early experiment rather than a production system. It is useful here as concrete evidence that the cryptography is implementable, separate from the harder question of changing bitcoin's consensus rules.